The strtok function is used to isolate sequential tokens in a null-terminated string, *source. These tokens are delimited in the string by at least one of the characters in *delimiters. The first time that strtok is called, *source should be specified; subsequent calls, wishing to obtain further tokens from the same string, should pass a null pointer instead. The separator string, *delimiters, must be supplied each time, and may change between calls.
The strtok function returns a pointer to the beginning of each subsequent token in the string, after replacing the separator character itself with a NUL character. When no more tokens remain, a null pointer is returned.
The strtok_r function has the same behavior as strtok, except a pointer to placeholder *[lasts> must be supplied by the caller.### Returns
strtok returns a pointer to the next token, or NULL if no more tokens can be found.
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**Authoritative source**: BUSMASTER DITA help source `strtok.dita`, compiled into `BUSMASTER.CHM` with the application.